Let me provide some numbers on the clones:
Firstly, we have the sending-off of regiments (2204 clones) in the ROTS novel, to serve as bodyguards for the governors.
Assuming, extremely conservatively, that they only were sent to sector capitals, and that a supermajority within Republic parlance refers to a 50%+1 majority, then we have 8,820,408 clonetroopers being sent off. Three times the supposed GAR, being used as bodyguards.
Bumping this up to a 2/3rds supermajority, with the same assumptions otherwise, we have 13,224,000 clonetroopers sent off. Four times the GAR now.
Going to the more plausible every member planet having a regiment arrive with a governor, but with the conservative number of sectors and using the Chommell sector as an average, then we have 317,534,688, or 105 times the GAR, being put on bodyguard duty.
Using the more likely sector amount, but with the same assumptions otherwise, we have 476,064,000, or 158 times the GAR, being put on bodyguard duty.
Taking the statements about 100-125 members planets per sector on the average, but with the conservative figures on the senate size, we have 992,295,900, or 330 GARs, being put on bodyguard duty.
Taking the more reasonable senate size figures and the 100-125 member planets per sector, we have 1,487,700,000, or 496 times the GAR being put on bodyguard duty.
Now then, if we take the Imperial principle of having a garrison force on every planet they control as being representative of Palpatine's early governors, we have to contend with the dependencies and colonies. They number 50 million. Assuming Chommell sector to be representative and using the conservative senate size, we have 2.646e12 clonetroopers on guard duty (note that they swamp out those on member planets by about three orders of magnitude).
Assuming that Chommell sector is representative and using the more realistic senate size, we have 3.9672e12 clonetroopers on guard duty.
Note that these are the troops Palpatine could afford to send off at the height of the war, without the Jedi noticing or caring, so they cannot be a large proportion of the real GAR, nor do they include actual garrisons, naval and fighter crews, the Coruscant police, or the line forces proper. He almost certainly won't accept my methodology as average or talk about how it's a brushfire war, but let us look at one of the most one-sided wars of the twentieth century, the invasion of Grenada by the US. The US still sent 10,000 troops, one-eleventh of the island's total population, to invade against 2,200 local and Cuban soldiers. That's a five-to-one advantage when the US had total air and naval superiority, with two carriers operating in support. Taking that as a member planet-sized "brushfire war" and scaling up to a galaxy with one million full member planets yields about ten billion soldiers on the victorious side. Mere millions is roughly equivalent to an FBI sting operation.
Some more fun numbers: the NYPD has one officer for every 221 and change people in New York, 37838 in total. Coruscant has, at a minimum, one trillion people. The Coruscant Police Department would therefore have 4,524,886,878 officers. That is 1,508 GARs. That is using minimalistic numbers for Coruscant. Using Dr. Saxton's estimate of at least one quadrillion, we have 4.5 trillion police officers on Coruscant, or 1,508,295 GARs. This is assuming that the planet is as regularly patrolled as New York City, of course.
The US has about 800,000 people employed as police officers
From here
The proportion of US police officers employed in New York is 4.73%. Assuming that Coruscant sucks up as much manpower as New York does, proportionately, we have a total of 95 trillion police officers in the galaxy as a whole, which is a ridiculously conservative number.
Feel free to use these numbers, but be aware that he is likely to deny them outright.